Watershed management practices by biological, biomechanical and mechanical operations are not only trying to solving watershed problems, but also in line with the sustainable development through improving the economic condition and living standards of stakeholders. Therefore, the present study was conducted to impact evaluation of the soil and water conservation practices on the sediment yield of Kan watershed in Tehran province using the data of the period of 1998-2018. The initial results from the practices simulation using the SWAT model showed that there was the large difference between the simulated and observed values, the model was recalibrated and validated after steps performance of the sensitivity analysis with the 2-SUFI algorithm. Based on the obtained results, the coefficient value of explanation in the calibration and validation stage of model obtained equal to 0.74 and 0.86, respectively, and the Nash-Sutcliffe index value was equal to 0.74 and 0.77, respectively, that these values showed the model had the high efficiency for simulation. Then the simulation of watershed management practices investigated on the watershed level and the results indicated if the management practices implement the sediment values will reduce. In such away that the sediment yield in the watershed reduced using practices simulation of terracing, masonry check dams, gabion check dams, loose stone dams, seeding and planting decreased with rates of 44.65, 26.72, 26.70, 8.03, 4.97 and 9.73 percent, respectively.